Oncogene-induced senescence is induced by Bcl-xL inhibition in vitro. PANC-1 and MIA Paca-2 cells were transfected with Bcl-xL siRNAs (si1, si2, si3) or negative control siRNA (NC) for 24 hours. After changing the medium, cells were incubated for an additional 24 hours (caspase-3/7 activity) and for 48 hours (WST assay, Western blot analysis, and SA–β-gal activity). (A) Caspase-3/7 activity in culture supernatants and cell viability was determined by the WST assay (n = 4). (B) Western blot of Bcl-xL and p21. (C) Representative images of PDAC cells stained for SA–β-gal activity and the percentage of SA–β-gal–positive cells. Scale bar: 100 μm. *P < .05.